Meta-Analysis of Heavy Metal Contents in Livestock and the Worldwide Potential Exposure to Human for Carcinogenic and NonCarcinogenic Risks

Livestock products are vital sources of protein and amino acids essential for human health. However, they may also expose consumers to harmful substances, including heavy metals. This study aimed to assess whether heavy metal concentrations, specifically lead, copper, zinc, cadmium, mercury, and arsenic, in various livestock products pose potential carcinogenic or non-carcinogenic risks. A meta-analysis of existing studies on heavy metal concentrations in livestock products was conducted to estimate exposure levels and associated health risks. Non-carcinogenic risk values were below 1, indicating minimal health risk. For lead and arsenic, known carcinogens, the estimated excess cancer risk (ECR) in beef cattle and sheep or goat products did not exceed 1×10⁻⁴ but was above 1×10⁻⁶. These findings suggest that while the probability of cancer incidence is low, there is still potential for carcinogenic harm from lead and arsenic in livestock products. Therefore, it is recommended that livestock products, particularly beef cattle and sheep, undergo contamination analysis before commercial distribution.